PB2173: IDENTIFICATION OF POTENTIAL THERAPEUTIC TARGETS OF BAICALIN INTERVENING GASTROINTESTINAL ACUTE GRAFT-VERSUS-HOST DISEASE BASED ON NETWORK PHARMACOLOGY AND WHOLE TRANSCRIPTOME SEQUENCING
Authors: J. fu, J. lin, L. xingyan, C. xing
Journal: HemaSphere (2022)

Background: Acute graft-versus-host disease (aGVHD) is one of the major complications of allo-HSCT1. Up to 60% of patients have gastrointestinal (GI) involvement, which may result in secretory diarrhea and abdominal pain2. Corticosteroid therapy is most often used as first-line treatment in patients, while the treatment is very limited3. Baicalin is an extract from huangqin, which exerts various protective effects on the intestinal system in modern studies4. However, its chemical and pharmacological mechanisms remain to be elucidated. Therefore, we try to characterize the potential molecular mechanism of baicalin intervening aGVHD with the combination of network pharmacology prediction with high-throughput sequencing. Aims: To identify potential therapeutic targets of baicalin intervening aGVHD and reveal its pharmacological mechanisms. Methods: The potential targets of baicalin were obtained from the TCMSP database, Swiss Target Prediction databaicalinse and Pharm Mapper. 4 serum samples from aGVHD patients and 4 control samples were sent for high-throughput sequencing. Then genes with significant differences (P<0.001 and |logFC|>2) were selected and intersected with therapeutic targets of baicalin. Potential targets were identified to establish interaction networks by STRING and Cytoscape. GO enrichment and KEGG pathway analyses were performed and visualized in R software. Molecular docking was performed to visualize the patterns of interactions between the baicalin and associated targeted proteins. Subsequently, transfer of mononuclear cell suspension (bone marrow + spleen) from Balb / c mice into CB6F1 mice irradiated with 60co X-ray via tail vein injection. Model group and treatment group were given 0.9 sodium chloride and baicalin by gavage respectively. Observation of pathological sections and immunohistochemistry (IHC) of core targets were executed based on the result of network pharmacology analysis. Results: 1. Targets Identification of baicalin on aGVHD In total, 293 targets of baicalin were obtained and 1025 differently expressed genes were identified (Fig 1). Then, 23 overlapping genes were extracted with 17 up-regulated genes and 6 down-regulated genes (Tab 1). 2. Network and Pathway Enrichment Analysis MMP9 (degree=9) and CCNA2 (degree=7) showed significant importance (Fig 2A). MAPK14(degree=14) and SRC (degree=12) were enriched in multiple pathways (Fig 2B). The biological process was mainly associated with inflammation, including regulation of inflammatory response (GO:0050727), positive regulation of cytokine production (GO:0001819) (Fig 3A). KEGG enrichment analysis revealed that the IL-17 signaling pathway was closely associated with baicalin intervention for aGVHD (Fig 3B). 3. Molecular docking between the core genes and baicalin Four core targets (MAPK14, SRC, MMP9 and CCNA2) were choosed to dock with baicalin (Fig 4) and MMP9 bound to baicalin best. 4. Experimental Validation Pathological observation showed that the mice with acute graft versus host disease in treated group had more complete intestinal mucosa (Fig 5A, B). Baicalin treatments decreased MMP9 protein levels in small intestinal tissues detected by IHC (Fig 5C, D). Image:Summary/Conclusion: Our study suggested baicalin conspicuously demonstrates multiple curative effects in aGVHD correlating with intricate and innumerable mechanisms and signaling pathways, mainly by mediating immune response pathways induced by inflammation.